Water treating compositions



Patented Nov. 13, 1951 UNITED STATES PATENT OFFICE WATER TREATING COMPOSITIONS John W. Lefiorge, Anniston, Ala., assignor to Monsanto Chemical Company, St. Louis, Mo., a.

corporation of Delaware No Drawing. Application December15, 1947,

Serial No. 791,936

about 1.0 to about 1.3, a compound or compounds which liberate a relatively water insoluble gas when contacted with water and a wetting rate retarder comprising an unsaturated aliphatic hydrocarbon compound containing in the hydrocarbon radical from 6 to 12 carbon atom per polar group, ormore particularly an unsaturated aliphatic hydrocarbon containing from 6 to 12 carbon atoms for each double bond in the'aliphatic h m to o Another object of the invention is to provide a water treating composition of substantially increased solution rate which contains a, water soluble molecularly dehydrated sodium phosphate havinga Nazo/PgOt molecular ratio of from 1.0 to 1.3, an alkalinity adjusting agent which liberates a substantially water insoluble gas upon reaction with the above phosphate and a hydrocarbon compound of the above type, which composition floats upon the surface of the water treated therewith until dissolved, or at least partially sinks toward the bottom of the dissolving vat and then is refloated by thebuoying action of the liberated gas until completely dissolved.

A further object is to provide a water treating composition including the above combination of ingredients, which disintegrates and spreads over the surfaces of the water treated and thus provides a non-matting or non-lumping material which possesses a substantially improved solution rate over that of similar compositions not containing a wetting rate retarder.

Other objects and advantages of the present invention will be apparent to those skilled in the art as the description proceeds.

Water soluble sodium metaphosphate is a well known and widely used water treating compound which is available commercially in the form of a glass, powder or flakes, but for various reasons hereinafter indicated, these products have not been entirely satisfactory.

For example, sodium hexametaphosphate in the form of broken glass is not convenient to handle and in addition is very slowly soluble. The flaked material readily goes into solution but is expensive to produce and has'the objectionable 8 Claims. (Cl. 252-175) property of sticking to or cutting the hands of the user. lumps when added to water and settles to the bottom of the dissolving vat in the form of a sticky gummy mass which dissolves at an ex tremely slow rate.

The matting tendency of powdered sodium hexametaphosphate may be counteracted pare tially by mixing therewith sodium carbonates and other gas liberating alkalinity adjusting agents, but this method or approach does not provide a satisfactory solution to the problem. For examp1e, if such mixtures are added to water, matting or lumping does not take place to the extent that it occurs with powdered sodium hexame'taph'os phate per se, but the wetting rate "of the phosphate powder and the gas liberation rate are so rapid that the buoying action of the gas is not of sufficient duration to insure complete solution of the mixture. The result is that appreciable amounts of sodium hexametaphosphate sink to the bottom of the dissolving vat and form a phosphate residue which dissolves very slowly.

Heretofore, it 'has beenproposed to solve'thef above problem by agglomerating mixtures or powdered sodium hexametaphosphate and sodium carbonates. This method achieved some measure of success but'is' subject to the disadvantage of being expensive and of causing an excessive amount of reversion which'seriously of the impairs the water softening properties product.

I have made the surprising discovery that if finely divided sodium hexametaphosphate, so-

dium carbonate and an aliphatic hydrocarbon compound of the above type are homogeneously blended together in the proportions hereinafter indicated, a water treating product of substantially improved solution rate is provided which has none of the objectionable properties mencommercial scale. J

The sodium carbonate in the above composition serves as an alkalinity'adjusting agentand also as a means of developing carbon dioxide which causes the product to float on the surfacef of the water. Thus, sodium carbonate liberates carbon dioxide by reaction with sodium hexa-l metaphosphate and the liberated gas forms b'ubt te. ll? %?-P Wee ies The powdered product mat up or the phosphate product. These bubbles buoy up the particles and cause the latter to float on the surfac of the water until completely dissolved.

The aliphatic hydrocarbon compounds of the present invention are somewhat repellent and retard the wetting rateof the sodium hexametaphosphate particles .and this has the desirable effect of causing the bubbles produced by' the liberated carbon dioxide to attach themselves to the above particles with the result that the latterr are buoyed up and floated on the surface of the. water. The wetting rate retarding action of the unsaturated hydrocarbon compoundsbringsabout a slower but more uniform reaction between the phosphate particles and th sodium carbonate and therefore the liberatedgasisame to float the particles upon the surface oflzlthei water for a period long enough to effect complete solution. These compounds also disperse" any floating lumps of the mixture which form on the surfaceand 'thus'not only aid in the prevention" ofjmatting but also increase the surface of'the particles exp'csedto the dissolvingaction'of the water treatedi The problems of matting and slow solution L rate are not restricted to sodium hexametaphosphate'as theyare encountered in all of the water soluble molecularly: dehydrated alkali metal phos phates having analkali metal-oxide/Pzos molecular'ratio of'from about 1 .0 tdabout 1.3 and it to be understood that the present invention isdirected'to all of the foregoing-phosphate and particularly to the Sodium and potassium phosphates within the above range.

' Fora more'complete understanding of the pres entinvention reference is maide'tdthe followingekarnples whichdemonstr'ate themark'ed increase in'solution' rate obtained by incorporatinganu'n saturated hydrocarbon compoundof the type hereinbefore indicatedwith rmixtures of sodium carbonate and water soluble molecularly dehydrated sodium phosphates having a; Na'zO/Pzos' molecular ratio within therange of from 1.0- t0'123."

Example I n I; r eaitn st at picnic C i f i' composediof accidenta- 80.837313 weightof' d e' e it lpr r n rli a e ktF 'firv of sodium acid pyrophosphate was thoroughly:

mixed with 6% by weight of sodium carbohateto" ll ld y.f l i il f these materials; A -gram safnple of the product wasaddd'to a bearer containing enters: ere ari'd'the time required to cemetery dissblve" material without agitation was etermine .11; was" found that a substantial proportion of the sample rapidly dissolved during theses liberating stage, but as soon. this was over; a pardon; thereof sank tome bottom of the beaker and" formed a phosphate residue which dissolved so slowly fl'i at a total (if 11 fli il ilit es walieqlliled fdi complete solution. 7 w

A similar mixture was". prepared aaa re 1% by weight of propylene olymer" was u'ni formly blended therewith. H;

AB-gram sample of th' productwa's'introdiiced into a" liter of water a'n'd' its solution rate (is termined in the manner described above. Itwas" found'that insteadfo'f setting freecarbon dio'igide' all'at once and leaving'a slowly dissolving residue] on'the bottom of;the"b'eal;er,,the hydrocarbon u e th h h eyim tri t read u on the surface of 'the 'water'andliberate th'abdv 4 gas slowly and uniformly with the result that the product floated and dissolved completely within a period of 6.5 minutes.

Example [I a A- finely divided phosphate composition consisting essentially of sodium septaphosphate (NasP'zOzz) was thoroughly mixed with 6% by I weight of sodium carbonate and a 5-gram sample of the resulting product was added to a liter of waterfor the purpose of determining its solution rate. As in Example I a substantial amountofthe'prgdiictrapidly dissolved during the gas ut 8- nawitn islf fiel r upgrapqagefm but a slowly dissolving residue was formed ontlieibottom of the beaker and it required 16* minutes to achieve complete solumower the entire sample.

The above experiment was repeated using the same composition to which 1% by weight of "propylene polymer had. beennadded, and in,- tirr'iately mixes, Thefr smting'pr dcuetf dissolve-a completely without agitation in'a period" of 5 minutes: i

The aboveexamples show that the proble matting or mi pixigis' solved by the d j tm propylenef 'o ym'er ,andithat' the,solu'tfo H of mixtures 'of sbdiumearbonate w the a-bov degree], Propylene polymer isian' a I mixture containing a major prop do decent which has'. ariiavei ag molecule hd'spaates is thereby intrastate surprising? of 185, a I refractive; 6X o fjl product may be var'ie'dfwidely-i tdmeeesp'ecifie requirements;- blilf for optimum results from the standpoint of detergent and water sdfthing" properties, it is pie'fer'red'f to maintain" the? e: I ponentstherofwithin'the'limitsspcified in the following formulation;

fllxpressedin term s dr" e sse rift fa l employing a gas liberating alkalinity adjusting 7 agent, that'the compositionlb e so proport p as to yield a pH in l %"soliitionjo f aboutfifitfi p e ed. However; ifafea' libe etiilacb fn t is" included n the" ompo t n which apesdepend upon'a 'part iculagrpHof sqlutiofi'to' asufficie'nt amountof gas the present nvention is dire ing 5,, I n I 438'Oat 25CT and the following distillat'idn range:

Degrees Ci arcane "Per cent by weight.

Phosphate composition as used above covers water soluble molecularly dehydrated alkali metal phosphates having an alkali metal oxide/P205 molecular ratio of about 1.0 to about 1.3. Stated difierently, this expression covers the above water soluble molecularly dehydrated alkali metal .phosphates or mixtures thereof in any of the various forms shown in the graph (Fig. 8) on page 460 of the article by E. P. Partridge et al. which is reported in vol. 63 of the J. Amer. Chemical Society, 1941. The expression Gas liberating compounds includes alkalinity adjusting agents such as sodium percarbonate, sodium carbonate, sodium bicarbonate or other compounds or combinations of compounds which hydrolyze or react together in the presence of water to yield a substantially water insoluble gas.

The unsaturated hydrocarbon compounds employed in producing non-matting, rapidly dissolving water treating products of the above type are those containing from 6 to 12 carbon atoms per polar group or more particularly those containing from 6 to 12 carbons in the hydrocarbon radical for each double bond. Examples of compounds within the foregoing class which yield the most satisfactory products are octene and .propylene polymer.

The amount of unsaturated compound employed in the water treating product may fluctuate considerably, but it is preferably maintained within the range of about 0.02% to 2% by weight. The optimum amount varies with the compound selected, but in general the higher the molecular weight or the greater the number of carbon atoms per polar group, the smaller is the amount of the unsaturated compound required. In the case of "propylene polymer, the best results are obtained by using this material in an amount equivalent to about 1% by weight.

In compounding the above product, the components may be mixed together in any desired order so long as thorough and uniform mixing is obtained.

The particle size of the alkali metal phosphates is not critical, but it is desirable to use material not coarser than 50 mesh, and preferably not coarser than 100 mesh.

The above description has been limited to compositions consisting essentially of water soluble molecularly dehydrated alkali metal phosphates, gas-liberating compounds which yield a substantially water insoluble gas 'upon contact with water and an unsaturated aliphatic hydrocarbon compound of the class hereinbefore defined. The invention, however, is not restricted thereto as various alkalinity adjusting compounds in addition to those specifically mentioned may be incorporated in the above compositions. For example, caustic soda, sodium sulfate, sodium bisulfate, sodium bisulfite, sodium metasilicate, trisodium orthophosphates, sodium pyrophosphates, sodium polyphosphates having a Nam/P205 molecular ratio above 1.3, and mixtures of these, and also the corresponding potassium salts may be employed if desired.

Where the gas-liberating compound yields gas upon contact with water irrespective of the pH of the composition, the above a kaline salts may be used in any desired proportions, but this is not true where gas-liberating alkalinity adjusting agents are employed, Thus, if sodium percarbonate, sodium carbonate, sodium bicarbonate or equivalent salts are used, the quantity of the alkalinity adiusting compounds must. be so proportioned as to provide a composition having a pH in 1% solution not exceeding about 8.0, otherwise matting will occur. The reason for this is that a pH above 8 either preventsthe reaction between the phosphates and the alkalinity adjusting agent from occurring or it retards the reaction rate to a point where the gas is not liberated rapidly enough to float the product. The result is that the phosphate com position sinks to the bottom of the dissolving vat and forms a veryslowly dissolving residue.

The present invention is limited solely by the claims attached hereto as part of the present specification.

I claim:

1. A substantially non-matting water treating composition consisting essentially of a substantially homogeneous mixture of the following materials in the indicated proportions: a water soluble molecularly dehydrated sodium phosphate having a sodium oxide/P205 molecular ratio of about 1.0 to about 1.3, 80%-96% by weight; a compound selected from the group consisting of sodium carbonate, sodium bicarbonate and sodium percarbonate, 20%-2% by weight; an

unsaturated aliphatic hydrocarbon selected from the group consisting of propylene polymer and octene, 0.02%-2% by weight.

2. A substantially non-matting water treating composition consisting essentially of a substantially homogeneous mixture of the following materials in the indicated proportions: a water soluble molecularly dehydrated sodium phosphate having a sodium oxide/P205 molecular ratio of about 1.0 to about 1.3, 88%-96% by weight; a compound selected from the group consisting of sodium carbonate, sodium bicarbonate and sodium percarbonate, 4%-10% by weight; an unsaturated aliphatic hydrocarbon selected from the group consisting of propylene polymer and octene, 0.02%-2% by weight.

3. A substantially non-matting water treating composition in accordance with claim 2 wherein the water soluble molecularly dehydrated sodium phosphate is sodium hexametaphosphate.

4. A substantially non-matting water treating composition in accordance with claim 2 wherein the water soluble molecularly dehydrated sodium phosphate is sodium septaphosphate.

5. A substantially non-matting water treating composition consisting essentially of a substantially homogeneous mixture of the following materials in the indicated proportions: a water soluble molecularly dehydrated sodium phosphate having a sodium oxide/P205 molecular ratio of about 1.0 to about 1.3, 88 %-96% by weight; a compound selected from the group consisting of sodium carbonate, sodium bicarbonate and sodium percarbonate, 4%10% by weight; propylene polymer, 0.02%-2% by weight.

6. A substantially non-matting water treating composition consisting essentially of a substan-- tially homogeneous mixture of the following materials in the indicated proportions: a water soluble molecularly dehydrated sodium phosphate having a sodium oxide/P205 molecular ratio of about 1.0 to about 1.3, 88%-96% by weight; a. compound selected from the group consisting of sodium carbonate, sodium bicarbonate and so- 7. *subs'tantiaHy non matfiin'gwater treat mg com'positio'n cofisisting essentially *of a. subsmx'a fially homogeneous mixture of sodium hexanieb'amhospha te, about 6% by weigmof soZi'iu'm barbona te and about 1% by weight of propylene mlymry L 1 8'. A substantial-1y non-matting water tl esifimg composition consisting essentially of a 'substan tiailly homogeneous mixture of sodium 'septaph'osphate, about 6% by we'i-ghb of-sod-imn carbonate a'iidabo'ut 1"% byweight'of propylene polymer? JOHN W. m 2 64 REFERENCES QITED I The 'iollowm'g rererepoe's 9.1g of record in "the file of this patent: UNITED STATES PATENTS Number Name Date Re.19,'7-19 Hall Oct. 8, 1935 1,717,553 Flanmi'er "at am. June-1'8, 1929 1,979,925 Zinn Nov. 6, 1934 w 2,244,158 l -lubbard-etal. June 3, 1941 2,414,369 Moose Jan/28, 1947 F RE G PATEN S Number Country Date Great Britain on. Nov. .12, .1940 

1. A SUBSTANTIALLY NON-MATTING WATER TREATING COMPOSITION CONSISTING ESSENTIALLY OF A SUBSTANTIALLY HOMOGENEOUS MIXTURE OF THE FOLLOWING MATERIALS IN THE INDICATED PROPORTIONS: A WATER SOLUBLE MOLECULARLY DEHYDRATED SODIUM PHOSPHATE HAVING A SODIUM OXIDE/P2O5 MOLECULAR RATIO OF ABOUT 1.0 TO ABOUT 1.3, 80%-96% BY WEIGHT; A COMPOUND SELECTED FROM THE GROUP CONSISTING OF SODIUM CARBONATE, SODIUM BICARBONATE AND SODIUM PERCARBONATE, 20%-2% BY WEIGHT; AN UNSATURATED ALIPHATIC HYDROCARBON SELECTED FROM THE GROUP CONSISTING OF "PROPYLENE POLYMER" AND OCTENE, 0.02%-2% BY WEIGHT. 